Sinkholes, leaking roofs, overflowing septic tanks and bomb threats. Now, a "bullet-planting" extortion racket. No wonder Manila's airport has been ranked among the world's worst.

The Ninoy Aquino International Airport (NAIA) was meant to honour the late democracy icon Benigno Aquino Jr, the father and namesake of the current Philippine president.

But in recent years, it has reeled from an unsavoury reputation among travellers for its sagging infrastructure, poor customer service, bribery involving staff and taxi drivers cheating passengers.

The NAIA has four terminals, three of which handle international flights.

In July, a 40-year-old Australian fell into a 0.6m-deep hole when part of the floor at the Terminal 2 arrival area gave way.

And in June, rainwater sprinkled all over the Terminal 1 departure area during a heavy downpour due to shabby repairs.

Last year, the same terminal stank when a septic tank overflowed. Members of a fringe group of China haters were also nabbed trying to plant explosives in the airport's toilets.

Terminal 1 is now nearly at the end of its first major renovation in 30 years. At a cost of 1.3 billion pesos (S$39 million), a contractor has been fixing and refurbishing the terminal's ceilings, plumbing, air-conditioning and toilets.

New check-in counters have been built and new lighting, conveyor belts and display boards installed.

The makeover has had an impact. In the 2014 list of the travel website The Guide To Sleeping In Airports, the NAIA is no longer the world's worst airport, a title it held from 2011 to 2013.

But it is still ranked by the website as the eighth worst in Asia.

Raul Dancel